Verifying Concurrent Stacks by Divergence-Sensitive Bisimulation

Abstract

The verification of linearizability -- a key correctness criterion for concurrent objects -- is based on trace refinement whose checking is PSPACE-complete. This paper suggests to use \emph{branching} bisimulation instead. Our approach is based on comparing an abstract specification in which object methods are executed atomically to a real object program. Exploiting divergence sensitivity, this also applies to progress properties such as lock-freedom. These results enable the use of \emph{polynomial-time} divergence-sensitive branching bisimulation checking techniques for verifying linearizability and progress. We conducted the experiment on concurrent lock-free stacks to validate the efficiency and effectiveness of our methods.